[feat] Add producer interceptor

[RobertIndie]

Master Issue: #150

Motivation

This is the producer interceptor implementation of #150.

Modifications

• Add ProducerInterceptor interface
• Add intercept and getInterceptors in ProducerConfiguration.
• Triggering the interceptor when beforeSend, onSendAcknowledgement, onPartitionsChange and close.

Verifying this change

• Make sure that the change passes the CI checks.

This change added tests.

Documentation

• doc-required
  (Your PR needs to update docs and you will update later)

• doc-not-needed
  (Please explain why)

• doc
  (Your PR contains doc changes)

• doc-complete
  (Docs have been already added)

[BewareMyPower]

All the tests should check what latch.wait returns and the side effects made by the different interceptors.

[BewareMyPower]

Could you solve the conflicts?

[RobertIndie]

Could you solve the conflicts?

Done. PTAL again. Thanks.

outdated

[BewareMyPower]

I've left two comments about the coding style. These should not be blockers so I dismissed my requested changes before.

[BewareMyPower]

@RobertIndie The main branch is broken due to a recent upgrade of macos-12 runner image. The fix is here: #199

[Anonymitaet]

Hi @RobertIndie, thanks for introducing this great feature!

As we discussed just now, for the doc side:

✅ Pulsar feature matrix

I've ticked the boxes of "Interceptors" for C++ producer and consumer.

✅ Pulsar client docs

Could you please provide the following tech inputs? TIA!

The following docs are only added to NEXT since this feature is server-independent.

• C++ > Producer > Interceptor

• C++ > Consumer > Interceptor